Devices which generate light by chemical means have existed for many years. The primary advantage to such devices is the generation of the light absent the generation of any consequential amount of heat. The uses of these devices have ranged from military (e.g., markers for shipwrecked seamen) to novelty (e.g., glow necklaces sold at fairs).
Formulas for creating chemiluminescent light are widely known and can be found in many patents originally assigned to American Cyanamid (e.g., U.S. Pat. No. 4,678,608). The construction of thin "ropes" or other flexible structures capable of emitting chemiluminescent light, on demand, are also well known.
Generally, chemiluminescent light is produced by the reaction of a catalyzed hydrogen peroxide solution with an oxalate solution. The main component of the oxalate solution is usually bis(6-carbopentoxy-2,4,5-trichlorophenyl)oxalate ("CPPO") which is mixed with dibutyl phthalate and a fluorescent dye (e.g., 9, 10 bis(phenylethynyl)anthracene). The hydrogen peroxide solution ("activator") typically includes a major portion of hydrogen peroxide, tertiary butanol, dimethyl phthalate and a catalyst (e.g., salicylate of sodium or other metal).
The fluorescent dye, present in the oxalate solution, is the ingredient which imparts color to the emitted light. Red, blue, pink, orange white and green are the most frequent colors imparted, depending upon the chosen dye.
The catalyst, included in the activator solution, functions as an initiator for the chemiluminescent reaction. Thus, the hydrogen peroxide solution and the oxalate solution must be kept apart until it is desired to generate light.
A typical chemiluminescent necklace is composed of two parts: an outside flexible plastic tube; and an inside frangible glass tube. Generally, the glass tube contains the oxalate solution and the plastic tube contains the activator solution. When the inner glass tube is broken, typically by bending the flexible plastic tube, the two components mix together and a chemical reaction takes place. This chemical reaction produces light of a particular color for a given length of time.
U.S. Pat. No. 5,158,349 discloses a multi-color chemical lighting device which purports to provide a plurality of colors, in a single flexible tube, without appreciable mixing of colors. The construction of this device is very straightforward, two or more frangible glass tubes ("ampules") are fitted, in a conventional manner, into an outer, flexible plastic tube. In at least an alternating pattern, the ampules contain dyes capable of causing the generation of different colored light. When the ampules are broken, a plurality of distinct color bands are initially created. Mixing of the color bands is stated to be avoided for diameters less than 0.3 inches, based on the discovery that "a critically long and narrow tube that is sealed at both ends can provide sufficient capillary wall resistance along the lateral mass of the reaction solution composition to practically preclude lateral admixing even under agitating conditions."
Studies of devices made in accordance with the teaching of U.S. Pat. No. 5,158,349 have revealed that, contrary to the statements in the specification, substantial mixing does occur, with and without agitation, when outer plastic tubes of inner diameters approaching 0.1 inches (2.5 mm) are employed. Thus, there is no prior art device which provides a multi-color chemiluminescent "rope" which maintains the colors in separate and distinct regions over time and after undergoing agitation.